1. Field of the Invention
This invention relates to an apparatus for water-cooling oil used in a hydraulic system for actuating an injection molding machine and for purifying said oil by filtration, which apparatus comprises two coaxial oil-conducting pipes, at least one cooling pipe extending in a first annular space between the oil-conducting pipes, a filter cartridge, which is surrounded by the inner oil-conducting pipe and defines with the inner oil-conducting pipe a second annular space for receiving oil to be filtered, which comes from the first annular space, and mounting means for securing the apparatus to a wall which defines an oil reservoir of the injection molding machine, which mounting means comprise a port member, which is mounted on the outer oil-conducting pipe and has a centering outer end portion, and a mounting block, which is disposed in the reservoir, wherein the port member and the mounting block contain each two passage sections, which are respectively coaxially included in a supply passage and a return passage for the oil.
2. Description of the Prior Art
In the operation of injection molding machines there is a widely varying demand for cooling the oil used in the hydraulic actuating means because that cooling demand will depend not only on the size of the injection molding machine but also on its mode of operation and on the physical properties of the material which is processed and also on the temperature of the ambient atmosphere. A decisive role is also played by the often varying temperature of the incoming temperature-control fluid or of the cooling water. In a tropical region the latter temperature in a room which is not air-conditioned may be higher by 20.degree. to 30.degree. C. than in countries having a rough climate in a room which is not heated or only slightly heated. A known apparatus of the kind described first hereinbefore has been disclosed in U.S. Pat. No. 4,669,533 and for the above-mentioned reasons must be designed for the maximum cooling demand, i.e., for a relatively high surplus cooling capacity. Because the cooling capacity will also depend on the size of the cooling apparatus, the latter will occupy a relatively large space on the outside surface of the base structure of the injection molding machine, particularly in that embodiment which has been described in lines 10 to 17 of column 9 of U.S. Pat. No. 4,669,533.